1. Field of the Invention:
The present invention relates to a novel process for the preparation of monomethylhydrazine. More particularly, the present invention relates to a process for the preparation of monomethylhydrazine which comprises reacting under heating hydrazine monohydrochloride with methanol in the presence of hydrazine dihydrochloride or methyl chloride.
2. Description of the Prior Art:
Monomethylhydrazine (hereinafter referred to as "MMH") is a very valuable compound which is widely used in the industries of pharmaceuticals and agricultural chemicals, the chemical industries, the aerospace and missile industries and other various industries.
As the process for the preparation of MMH, there are known so-called modified Raschig's processes such as a process comprising reacting monomethylamine with chloroamine obtained by reacting ammonia with sodium hypochlorite and a process comprising reacting monomethylurea and sodium hypochlorite with sodium hydroxide. These processes are not satisfactory from the industrial viewpoint, because the yield of MMH is low and the concentration of formed MMH in the reaction mixture liquid is low to render the purification step complicate and increase the manufacturing cost. It also is known that alkylhydrazines are formed by reaction of alkyl halides with hydrazine. However, when hydrazine is reacted with a methyl halide, by-products such as assymetric dimethylhydrazine, symmetric dimethylhydrazine and trimethylhydrazinium halide are formed in addition to intended MMH. Accordingly, the step of separating the intended product is complicated and the yield is low. Therefore, this process has not been carried out on an industrial scale.